Tips and Tricks
Service That Differential Tip (added Jun 2002)
If you are running a “Limited Slip Differential” such as a Power-lock, Track-lock, Traction Lock, Governor Lock or Eaton Posi, it’s a good idea to change the oil every 20 to 25 thousand miles. These positraction units have friction discs that will wear on turns when the discs are required to slip to allow your outside tire to make more revolutions than your inside tire. The worn material can build up and contaminate the oil.
Remove the cover when the unit is warm which will allow the oil to drain more efficiently. DO NOT spray any solvents or cleaners into the housing as this can damage the friction discs. Inspect the gear teeth for any chips or loss of case hardening on the power side of the teeth. Also look for any undercutting on the spider gears and side gears. This usually will show up on the side that gets the load under acceleration.
If all looks OK, replace the cover after cleaning both surfaces, using a new gasket or silicone sealant. Install one quart of the proper gear oil for your differential, and then add one 4 oz. Bottle of friction modifier and top off with gear oil. Replace the fill plug and drive the rig around the block making slow turns in both directions to mix the oil and additive and to lap the fresh mixture into the clutches.
If you have a 9” ford differential there is no cover to remove and usually no drain plug either so the best you can do is to jack up the rear axle assembly, remove the oil fill plug located in the nose piece, place a drain pan under the pumpkin and let the engine idle in reverse which will pump the oil out of the 3rd member. Once the oil coming out of the fill plug hole has slowed to a trickle, shift the transmission into neutral and shut off the engine. Install one quart of the proper gear oil for your differential, and then add one 4 oz. Bottle of friction modifier and top off with gear oil. Replace the fill plug and drive the rig as previously described.
Four-Wheel Drive Maintenance Tip (added May 2002)
Use it or loose it!
Now that summer is approaching many of you won’t be using much 4-wheel drive unless you are hard-core and wheel often. But letting that expensive running gear remain dormant for months at a time is a definite NO NO. Once a month lock in your hubs and take a short drive, 2 or 3 miles should be enough to throw around some gear lube and build a little heat in the differential and the u-joints which will help to dissipate moisture and prevent the seals from sticking to dry or rusted steel parts. You can accomplish the same thing by just engaging the transfer case and you won’t even have to get out of your rig, but do not do both at the same time unless you are on a gravel road or some loose surface or you will put a bind into the drive train. For those of you that have automatic locking hubs, make sure you are on a loose surface such as that gravel road before proceeding with this tip. If you can’t find a suitable loose surface, then engage 4 wheel drive and drive slowly, straight ahead for several hundred feet, avoiding any turning of the steering which would increase the rotational error and cause binding in the drive train. If you should have any difficulty shifting back into 2-wheel drive, put your transmission into reverse and slowly back up while attempting to gently move the transfer case shifter toward the 2 wheel drive position.
"V" Seal Trick (added Apr 2002)
Problem: The previous owner of your Jeep liked to play in mud bogs and water holes but neglected to do the required maintenance like re-packing the wheel bearings and changing the contaminated oil in the boxes. You have discovered that the spindles are so badly rust pitted that they will not allow your front wheel seals to properly seat against the spindle and also the pitting is acting like a grinder and wipes out the seals prematurely so wheel bearing grease is getting all over the brakes.
Solution: ’77 and newer Jeeps and ’73 and newer Chevrolet 4x4s with solid front axle assemblies use a “V” seal on the outer front axle to protect the needle bearing located inside the rear of the spindle. This needle bearing supports the outer axle as it passes through the spindle on its way to the locking hub. (Earlier spindles used a bronze bushing instead of a bearing.) Slide one of these “V” seals onto your spindle and push it up against the flange of the spindle that holds the spindle to the steering knuckle. Smear some grease onto the outside lip of the “V” seal and also on the face of your new front wheel bearing seal and when the wheel bearing hub is installed to the spindle the two seals will come in contact with each other and you will have a double seal that cures the problem. This is not a bad idea for you to use even if your spindles are perfect.
Fast Idle with the Flip of a Switch (added Mar 2002)
Problem: Your on a side hill but with you front end up in the air holding your brakes because you can't go anywhere due to someone having trouble in front of you and you can't back up because there is another rig holding his brakes waiting on you and you wish you had three feet--one for the clutch, one for the brake and one for the throttle--so you can keep it running at a little faster idle than usual because it's loading up. You obviously are running with a stick transmission and a carburetor.
Solution: Go to a wrecking yard and buy a fast idle solenoid (used on many domestic vehicles) and mount it to the carburetor or manifold so that when activated, the plunger will protrude and come in contact with the throttle linkage to hold a fast idle for you. Run a wire from the solenoid to a toggle switch on your dash and power the switch with a fused wire circuit that is hot only with the ignition in the on, or run position. This also comes in handy on cold winter mornings and when stuck in traffic and your fan is not pulling enough air to keep the engine cool.
Shock Absorber Mounting Tip (added Feb 2002)
Problem: You can't seem to find a front shock absorber that has enough travel without moving your upper shock mount way up and you refuse to CHOP UP your cherry fender to make room for the new mount.
Solution: Mount the shocks at an angle by relocating them behind the front axle. First cut the hex heads off of two long 5/8 diameter bolts and weld one to the back of each of your front u-bolt plates. Leave approximately 2” of the threaded end extending past the outside edge of each plate, tack weld a flat washer to the bolt for an inner stop for the shocks lower grommet. Next, pull out your shock to its mid point (half way between fully collapsed and fully extended) and slide it on to your new lower mount. Now swing the shock up along the frame until you find the optimum location for a new $5.00 shock stud. Drill a 1/2 “ hole in the frame and bolt on the stud. Finish bolting the shocks into place and your done.
The reason this works is that a shock that is mounted vertically will require 1 inch of travel for each inch the axle moves thus requiring a shock of great length to allow for maximum articulation of the suspension, however a shock that is mounted at an angle might only travel 50 to 75% as much as the axle so a shorter shock can be used.
Driving Lights Wiring Trick (added Jan 2002)
Problem: You are cruising on a dark country road with your driving lights on when suddenly an oncoming car rounds a corner and begins flashing his lights at you because you’re blinding him. You reach towards your dash to flip off your day lighters but you cant seem to find the switch so you take your eyes off the road to find it before he hits you head on. NOT GOOD!
Solution: If your driving lights are powered by a relay, you simply run the hot lead to your dash switch from the HIGH BEAM post of your foot operated headlight kick down switch. When your headlights are on LOW BEAM, no current goes to your dash switch and when you step on the switch for HIGH BEAMS your driving lights will come on if the dash switch is in the on position.